This invention relates to a sealed letter which is used chiefly for mailing a letter paper such as a bill, a notice or the like suitably printed by a printer without failing.
As for a sealed letter of this kind, there has been hitherto known a type in which an address and any other necessary descriptive matters such as a sum of money or other correspondence items are printed out on predetermined portions of letter paper by a printer of a computer, and the resultant correspondence letter paper is folded and the peripheral portions of the folded one are adhered together to form a sealed letter. To adhere the peripheral portions of the folded letter paper together, the letter paper, in general, is so prepared, prior to being folded, that ruled lines or other necessary matters are printed by an offset duplicator at predetermined portions on the blank of paper and thereafter the resultant letter paper is coated at predetermined peripheral portions with a heat sensitive or pressure sensitive adhesive agent. The letter paper thus prepared as above is applied with the foregoing printing of the address and so on by the printer of the computer and thereafter is folded and the peripheral portions of the folded one are adhered together by applying the heat or pressure to the coating, resulting in a sealed letter.
This conventional type of sealed letter involves various inconveniences as described below:
Recently, among various types of printers, use of a thermal type one has been on the increase and a large quantity thereof are used, but if this thermal printer is used for the letter paper coated with the adhesive agent as mentioned above, the adhesive agent is heated to melt at the time of printing the necessary items on the letter paper to cause trouble to the printer such as blocking to printing. Further, it is necessary for the letter paper to provide for a margin to paste up for applying the adhesive agent thereto, so that the overlap width is not effective for a corresponding part of the letter paper. Furthermore, since the sealed letter is formed by folding and adhering the letter paper, the number of folding thereof is limited, and accordingly the sealed letter folded in four, for instance, is difficult to obtain.
In addition, the letter paper is printed with feed holes for a printer on both side edges thereof, so that it is impossible to form the same into one having a series of separable sections as required for a letter paper having a series of separable printed forms, for statement of payment for instance.
The object of this invention is to provide a sealed letter which is a combination of such letter paper without coating any adhesive agent thereon that is suitable for printing out necessary descriptive matters thereon even by a thermal printer without causing any trouble thereto and separate sealable covering sheets for enclosing the foregoing printed letter paper therein, so that the printed letter paper is foldable any desired number of times and also any additional sheet such as a printed matter or the like can be enclosed therein, and accordingly a large number of the sealed letters can be made in succession in conjunction with a computer.
According to this invention, there is provided a sealed letter characterized in that letter paper on which an address and other descriptive matters are printed is covered, at its front surface, with a front sheet made of transparent paper laminated, at least at its rear surface, with a transparent and thermal adhering synthetic resin film, and is covered at its rear surface with a rear sheet made of any desired paper material, and the front sheet and the rear sheet are adhered together by heat at their peripheral portions to form an enclosed sealed portion.
Next, the process for making the sealed letter of this invention and the effect thereof will be explained as follows:
Any necessary matters of correspondence such as an address and a sum of money, for instance, or others are printed out on predetermined portions of a letter paper by a printer connected to a computer, and the resultant correspondence letter paper is so folded a desired number of times to form a folded paper of a predetermined size so that the address printed thereon may appear on the front or top surface of the folded paper.
The folded letter paper is covered, at its front surface bearing the address printed thereon, with a front sheet made of transparent paper which is laminated, at its rear surface, with a transparent and thermal adhering synthetic resin film, and the folded letter paper is covered, at its rear surface, with a rear sheet made of any desired paper material, which may be the same material as the front sheet or ordinary paper such as kraft paper or the like, for instance, and the front sheet and the rear sheet are adhered together by heat at their peripheral portions to form an enclosed sealed envelope, so that a sealed letter is produced.
With the sealed letter, the address of the letter paper can be read through the transparent front sheet, and the front sheet and the rear sheet are chiefly composed of paper material, so that the sealed letter never does lose its proper rigidity, and consequently can maintain its predetermined shape of the sealed letter, until broken manually by an addressee.
Additionally, since the letter paper is not coated with a thermal adhering agent, a thermal printer can be free from any trouble hitherto caused by the adhesive agent, and the manner of folding the letter paper is a matter of discretion except the condition that the address has to appear on the front side, so that even a large-sized letter paper can be formed into a folded small-sized one such as a fourfold one or eightfold one, and thus a lot of information can be communicated by a sealed letter.